Andrew Gideon wrote in message gonline.com...
Did I misunderstand my reading on the subject, or should the Manifold
Pressure on an engine that's off be the local atmospheric pressure?

I've just noticed that this is not the case in my little R182.

It should be the same as ambient pressure, but not necessarily the
same a altimeter setting. Altimeter setting is not pressue but some
made up number that makes the altimeter read correctly (that's
actually the definition!).

-Robert